Soybean cultivar 93-13892

ABSTRACT

A novel soybean cultivar, designated 93-13892, is disclosed. The invention relates to the seeds of soybean cultivar 93-13892, to the plants of soybean 93-13892 and to methods for producing a soybean plant produced by crossing the cultivar 93-13892 with itself or another soybean variety. The invention further relates to hybrid soybean seeds and plants produced by crossing the cultivar 93-13892 with another soybean cultivar.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinctive soybean cultivar,designated 93-13892. There are numerous steps in the development of anynovel, desirable plant germplasm. Plant breeding begins with theanalysis and definition of problems and weaknesses of the currentgermplasm, the establishment of program goals, and the definition ofspecific breeding objectives The next step is selection of germplasmthat possess the traits to meet the program goals. The goal is tocombine in a single variety an improved combination of desirable traitsfrom the parental germplasm. These important traits may include higherseed yield, resistance to diseases and insects, better stems and roots,tolerance to drought and heat, and better agronomic quality.

Choice of breeding or selection methods depends on the mode of plantreproduction, the heritability of the trait(s) being improved, and thetype of cultivar used commercially (e.g., F₁ hybrid cultivar, purelinecultivar, etc.). For highly heritable traits, a choice of superiorindividual plants evaluated at a single location will be effective,whereas for traits with low heritability, selection should be based onmean values obtained from replicated evaluations of families of relatedplants. Popular selection methods commonly include pedigree selection,modified pedigree selection, mass selection, and recurrent selection.

The complexity of inheritance influences choice of the breeding method.Backcross breeding is used to transfer one or a few favorable genes fora highly heritable trait into a desirable cultivar. This approach hasbeen used extensively for breeding disease-resistant cultivars. Variousrecurrent selection techniques are used to improve quantitativelyinherited traits controlled by numerous genes. The use of recurrentselection in self-pollinating crops depends on the ease of pollination,the frequency of successful hybrids from each pollination, and thenumber of hybrid offspring from each successful cross.

Each breeding program should include a periodic, objective evaluation ofthe efficiency of the breeding procedure. Evaluation criteria varydepending on the goal and objectives, but should include gain fromselection per year based on comparisons to an appropriate standard,overall value of the advanced breeding lines, and number of successfulcultivars produced per unit of input (e.g., per year, per dollarexpended, etc.).

Promising advanced breeding lines are thoroughly tested and compared toappropriate standards in environments representative of the commercialtarget area(s) for three or more years. The best lines are candidatesfor new commercial cultivars; those still deficient in a few traits maybe used as parents to produce new populations for further selection.

These processes, which lead to the final step of marketing anddistribution, usually take from eight to 12 years from the time thefirst cross is made. Therefore, development of new cultivars is atime-consuming process that requires precise forward planning, efficientuse of resources, and a minimum of changes in direction.

A most difficult task is the identification of individuals that aregenetically superior, because for most traits the true genotypic valueis masked by other confounding plant traits or environmental factors.One method of identifying a superior plant is to observe its performancerelative to other experimental plants and to a widely grown standardcultivar. If a single observation is inconclusive, replicatedobservations provide a better estimate of its genetic worth.

The goal of plant breeding is to develop new, unique and superiorsoybean cultivars and hybrids. The breeder initially selects and crossestwo or more parental lines, followed by repeated selfing and selection,producing many new genetic combinations. The breeder can theoreticallygenerate billions of different genetic combinations via crossing,selfing and mutations. The breeder has no direct control at the cellularlevel. Therefore, two breeders will never develop the same line, or evenvery similar lines, having the same soybean traits.

Each year, the plant breeder selects the germplasm to advance to thenext generation. This germplasm is grown under unique and differentgeographical, climatic and soil conditions, and further selections arethen made, during and at the end of the growing season. The cultivarswhich are developed are unpredictable. This unpredictability is becausethe breeder's selection occurs in unique environments, with no controlat the DNA level (using conventional breeding procedures), and withmillions of different possible genetic combinations being generated. Abreeder of ordinary skill in the art cannot predict the final resultinglines he develops, except possibly in a very gross and general fashion.The same breeder cannot produce the same cultivar twice by using theexact same original parents and the same selection techniques. Thisunpredictability results in the expenditure of large amounts of researchmonies to develop superior new soybean cultivars.

The development of new soybean cultivars requires the development andselection of soybean varieties, the crossing of these varieties andselection of superior hybrid crosses. The hybrid seed is produced bymanual crosses between selected male-fertile parents or by using malesterility systems. These hybrids are selected for certain single genetraits such as pod color, flower color, pubescence color or herbicideresistance which indicate that the seed is truly a hybrid. Additionaldata on parental lines, as well as the phenotype of the hybrid,influence the breeder's decision whether to continue with the specifichybrid cross.

Pedigree breeding and recurrent selection breeding methods are used todevelop cultivars from breeding populations. Breeding programs combinedesirable traits from two or more cultivars or various broad-basedsources into breeding pools from which cultivars are developed byselfing and selection of desired phenotypes. The new cultivars areevaluated to determine which have commercial potential.

Pedigree breeding is used commonly for the improvement ofself-pollinating crops. Two parents which possess favorable,complementary traits are crossed to produce an F₁. An F₂ population isproduced by selfing one or several F₁ 's. Selection of the bestindividuals may begin in the F₂ population; then, beginning in the F₃,the best individuals in the best families are selected. Replicatedtesting of families can begin in the F₄ generation to improve theeffectiveness of selection for traits with low heritability. At anadvanced stage of inbreeding (i.e., F₆ and F₇), the best lines ormixtures of phenotypically similar lines are tested for potentialrelease as new cultivars.

Mass and recurrent selections can be used to improve populations ofeither self- or cross-pollinating crops. A genetically variablepopulation of heterozygous individuals is either identified or createdby intercrossing several different parents. The best plants are selectedbased on individual superiority, outstanding progeny, or excellentcombining ability. The selected plants are intercrossed to produce a newpopulation in which further cycles of selection are continued.

Backcross breeding has been used to transfer genes for a simplyinherited, highly heritable trait into a desirable homozygous cultivaror inbred line which is the recurrent parent. The source of the trait tobe transferred is called the donor parent. The resulting plant isexpected to have the attributes of the recurrent parent (e.g., cultivar)and the desirable trait transferred from the donor parent. After theinitial cross, individuals possessing the phenotype of the donor parentare selected and repeatedly crossed (backcrossed) to the recurrentparent. The resulting plant is expected to have the attributes of therecurrent parent (e.g., cultivar) and the desirable trait transferredfrom the donor parent.

The single-seed descent procedure in the strict sense refers to plantinga segregating population, harvesting a sample of one seed per plant, andusing the one-seed sample to plant the next generation. When thepopulation has been advanced from the F₂ to the desired level ofinbreeding, the plants from which lines are derived will each trace todifferent F₂ individuals. The number of plants in a population declineseach generation due to failure of some seeds to germinate or some plantsto produce at least one seed. As a result, not all of the F₂ plantsoriginally sampled in the population will be represented by a progenywhen generation advance is completed.

In a multiple-seed procedure, soybean breeders commonly harvest one ormore pods from each plant in a population and thresh them together toform a bulk. Part of the bulk is used to plant the next generation andpart is put in reserve. The procedure has been referred to as modifiedsingle-seed descent or the pod-bulk technique.

The multiple-seed procedure has been used to save labor at harvest. Itis considerably faster to thresh pods with a machine than to remove oneseed from each by hand for the single-seed procedure. The multiple-seedprocedure also makes it possible to plant the same number of seeds of apopulation each generation of inbreeding. Enough seeds are harvested tomake up for those plants that did not germinate or produce seed.

Descriptions of other breeding methods that are commonly used fordifferent traits and crops can be found in one of several referencebooks (e.g., Allard, 1960; Simmonds, 1979; Sneep et al., 1979; Fehr,1987).

Proper testing should detect any major faults and establish the level ofsuperiority or improvement over current cultivars. In addition toshowing superior performance, there must be a demand for a new cultivarthat is compatible with industry standards or which creates a newmarket. The introduction of a new cultivar will incur additional coststo the seed producer, the grower, processor and consumer; for specialadvertising and marketing, altered seed and commercial productionpractices, and new product utilization. The testing preceding release ofa new cultivar should take into consideration research and developmentcosts as well as technical superiority of the final cultivar. Forseed-propagated cultivars, it must be feasible to produce seed easilyand economically.

Soybean, Glycine max (L), is an important and valuable field crop. Thus,a continuing goal of plant breeders is to develop stable, high yieldingsoybean cultivars that are agronomically sound. The reasons for thisgoal are obviously to maximize the amount of grain produced on the landused and to supply food for both animals and humans. To accomplish thisgoal, the soybean breeder must select and develop soybean plants thathave the traits that result in superior cultivars.

SUMMARY OF THE INVENTION

According to the invention, there is provided a novel soybean cultivar,designated 93-13892. This invention thus relates to the seeds of soybeancultivar 93-13892, to the plants of soybean 93-13892 and to methods forproducing a soybean plant produced by crossing the soybean 93-13892 withitself or another soybean line.

DEFINITIONS

In the description and tables which follow, a number of terms are used.In order to provide a clear and consistent understanding of thespecification and claims, including the scope to be given such terms,the following definitions are provided:

Maturity Date. Plants are considered mature when 95% of the pods havereached their mature color. The number of days are either calculatedfrom September 1 or from the planting date.

Seed Yield (Bushels/Acre). The yield in bushels/acre is the actual yieldof the grain at harvest.

Lodging Resistance. Lodging is rated on a scale of 1 to 5. A score of 1indicates erect plants. A score of 2.5 indicates plants are leaning at a450° angle in relation to the ground and a score of 5 indicates plantsare laying on the ground.

Phytophthora Tolerance. Tolerance to Phytophthora root rot is rated on ascale of 1 to 5, with a score of 1 being the best or highest toleranceranging down to a score of 5 which indicates the plants have notolerance to Phytophthora.

Emergence. This score indicates the ability of the seed to emerge whenplanted 3" deep in sand and with a controlled temperature of 25° C. Thenumber of plants that emerge each day are counted. Based on this data,each genotype is given a 1 to 5 score based on its rate of emergence andpercent of emergence. A score of I indicates an excellent rate andpercent of emergence, an intermediate score of 2.5 indicates averageratings and a 5 score indicates a very poor rate and percent ofemergence.

Iron-Deficiency Chlorosis. Plants are scored 1 to 5 based on visualobservations. A score of 1 means no stunting of the plants or yellowingof the leaves and a score of 5 indicates the plants are dead or dyingcaused by iron-deficiency chlorosis, a score of 2.5 means plants haveintermediate health with some leaf yellowing.

Brown Stem Rot. This is a visual disease score from 1 to 5 comparing allgenotypes in a given test. The score is based on leaf symptoms ofyellowing and necrosis caused by brown stem rot. A score of I indicatesno symptoms. Visual scores range to a score of 5 which indicates severesymptoms of leaf yellowing and necrosis.

Shattering. The amount of pod dehiscence prior to harvest. Poddehiscence involves seeds falling from the pods to the soil. This is avisual score from 1 to 5 comparing all genotypes within a given test. Ascore of 1 means pods have not opened and no seeds have fallen out. Ascore of 2.5 indicates approximately 50% of the pods have opened, withseeds falling to the ground and a score of 5 indicates 100% of the podsare opened.

Plant Height. Plant height is taken from the top of soil to top node ofthe plant and is measured in inches.

Seed Protein Peroxidase Activity. Seed protein peroxidase activity isdefined as a chemical taxonomic technique to separate cultivars based onthe presence or absence of the peroxidase enzyme in the seed coat. Thereare two types of soybean cultivars, those having high peroxidaseactivity (dark red color) and those having low peroxidase activity (nocolor).

DETAILED DESCRIPTION OF THE INVENTION

Soybean cultivar 93-13892 has superior characteristics and was developedfrom the cross A5403 and DP3589. In the winter of 1991-1992, F₁ plantswere advanced to F₂ under lights in Costa Rica. In the summer and fallof 1992, F₂ plants advanced to F₄ by bulk pod method in Costa Rica. Inthe spring of 1993, F₄ plants were pulled and threshed individually inCosta Rica. In the summer of 1993, F₅ plants tracing to a single F₄plant were composited and determined to be breeding true forcharacteristics described in this application.

93-13892 is an early group V variety. 93-13892 has superior yield,taller growth and disease resistance compared to other early group Vvarieties. 93-13892 has purple flowers, gray pubescence and tan pods.Seeds average 3000 per pound and are shiny yellow with buff to imperfectblack hila, depending on environmental effects. 93-13892 is resistant torace 3 Soybean Cyst Nematode and Stem Canker. This variety is fieldtolerant to Phytophthora root rot and susceptible to Root KnotNematodes.

Some of the criteria used to select in various generations include: seedyield, lodging resistance, emergence, disease tolerance, maturity, lateseason plant intactness, plant height and shattering resistance.

The cultivar has shown uniformity and stability for the traits, asdescribed in the following variety description information. It has beenself-pollinated a sufficient number of generations with carefulattention to uniformity of plant type. The line has been increased withcontinued observation for uniformity. Soybean cultivar 93-13892 has thefollowing morphologic and other characteristics (based primarily on datacollected at Scott, Miss.).

VARIETY DESCRIPTION INFORMATION

1. Seed Shape: Spherical Flattened (L/W ratio>1.2; L/T ratio=<1.2)

2. Seed Coat Color (Mature Seed)--Yellow

3. Seed Coat Luster (Mature Hand Shelled Seed): Shiny

4. Seed Size (Mature Seed)--15 grams per 100 seeds

5. Hilum Color (Mature Seed)--Imperfect black

6. Cotyledon Color (Mature Seed)--Yellow

7. Hypocotyl Color--Light purple below cotyledons

8. Leaflet Shape--Ovate

9. Leaflet Size--Medium

10. Leaflet Color--Medium Green

11. Flower Color--Purple

12. Pod Color--Tan

13. Plant Pubescence Color--Gray

14. Plant Types--Bushy

15. Plant Habit--Determinate

16. Maturity Group: V

17. Disease Reaction:

Bacterial Pustule (Xanthomonas phaseoli var. Sojensis)--Resistant

Wildfire (Pseudomonas tabaci)--Resistant

Frogeye Leaf Spot (Cercospora sojina)--Moderately Resistant

Target Spot (Corynespora cassiicola)--Resistant

Stem Canker (Diaporthe phaseolorum var. Caulivora)--Resistant

Phytophthora Rot (Phytophthora megasperma var. sojae):

    ______________________________________                                               Race 1       Field tolerant                                            ______________________________________                                    

Soybean Cyst Nematode (Heterodera glycines)

    ______________________________________                                               Race 3       Resistant                                                   Race 14 Susceptible                                                         ______________________________________                                    

Southern Root Knot Nematode (Meloidogyne Incognits)--Susceptible

Peanut Root Knot Nematode (Meloidogyne arenaris)--Susceptible

18. Insect Reaction:

Potato Leaf Hopper (Empoasca fabae)--Resistant

19. Physiological Responses:

High Chloride Soils--Susceptible

20. Plant Lodging Score: 1.9

This invention is also directed to methods for producing a soybean plantby crossing a first parent soybean plant with a second parent soybeanplant, wherein the first or second soybean plant is the soybean plantfrom the line 93-13892. Further, both first and second parent soybeanplants may be from the cultivar 93-13892. Therefore, any methods usingthe cultivar 93-13892 are part of this invention: selfing, backcrosses,hybrid breeding, and crosses to populations. Any plants produced usingcultivar 93-13892 as a parent are within the scope of this invention. Asused herein, the term "plant" includes plant cells, plant protoplasts,plant cells of tissue culture from which soybean plants can beregenerated, plant calli, plant clumps, and plant cells that are intactin plants or parts of plants, such as pollen, flowers, seeds, pods,leaves, stems, and the like. Thus, another aspect of this invention isto provide for cells which upon growth and differentiation produce thecultivar 93-13892.

The cultivar 93-13892 is similar to A5547. While similar to A5547, thereare numerous differences including: 93-13892 has purple flowers andA5547 has white flowers. In addition, 93-13892 is susceptible to race 14of Soybean Cyst Nematode whereas A5547 is resistant.

TABLES

In the Tables that follow, the traits and characteristics of soybeancultivar 93-13892 are compared to several competing varieties ofcommercial soybeans of similar maturity. In the tables, column 1 showsthe claimed variety along with competing varieties. Column 2 shows theyield in bushels/acre for the instant invention and the competitorvarieties. Column 3 indicates the days to maturity either earlier ("-")or later ("+") than DP3519. Column 4 shows the plant height in inchesfor each variety. Column 5 indicates the plant lodging for the instantinvention and the competitor varieties. Lodging is rated 1=Best and5=Worst.

                  TABLE 1                                                         ______________________________________                                        COMBINED AGRONOMIC DATA - ALL LOCATIONS                                                      BU/A   MAT       HGT  LDG                                      ______________________________________                                        Number of Locations                                                                          35     19        35   35                                         93-13892 52.20 +2.00 27.00 1.90                                               DP3519 47.10 0.00 23.00 1.30                                                  A5547 46.00 +3.00 23.00 1.20                                                ______________________________________                                    

                  TABLE 2                                                         ______________________________________                                        COMBINED AGRONOMIC DATA - MIDSOUTH LOCATIONS                                                 BU/A   MAT       HGT  LDG                                      ______________________________________                                        Number of Locations                                                                          27     17        27   27                                         93-13892 50.40 +2.00 25.00 1.80                                               A5547 45.90 +3.00 21.00 1.10                                                  DP3519 45.60 0.00 21.00 1.20                                                ______________________________________                                    

Deposit Information

A deposit of the soybean seed of this invention is maintained byDeltapine Seed, 100 Main Street, Scott, Miss. 38772. Access to thisdeposit will be available during the pendency of this application topersons determined by the Commissioner of Patents and Trademarks to beentitled thereto under 37 CFR 1.14 and 35 USC 122. Upon allowance of anyclaims in this application, all restrictions on the availability to thepublic of the variety will be irrevocably removed by affording access toa deposit of at least 2,500 seeds of the same variety with the AmericanType Culture Collection, Manassas, Va.

Although the foregoing invention has been described in some detail byway of illustration and example for purposes of clarity andunderstanding, it will be obvious that certain changes and modificationsmay be practiced within the scope of the invention, as limited only bythe scope of the appended claims.

What is claimed is:
 1. A soybean seed designated 93-13892 and havingATCC Accession No.
 2. A plant or its parts, each produced by the seed ofclaim
 1. 3. Pollen of the plant of claim
 2. 4. An ovule of the plant ofclaim
 2. 5. A soybean plant having all of the physiological andmorphological characteristics of the soybean plant of claim
 2. 6. Tissueculture of the plant of claim
 2. 7. A soybean plant regenerated from thetissue culture of claim 6, said plant having all the physiological andmorphological characteristics of the plant of claim
 2. 8. A method forproducing a hybrid soybean seed comprising crossing a first parentsoybean plant with a second parent soybean plant and harvesting theresultant hybrid soybean seed, wherein said first or second parentsoybean plant is the soybean plant of claim
 2. 9. A hybrid seed producedby the method of claim
 8. 10. A hybrid plant or its parts, each producedby growing said hybrid soybean seed of claim
 9. 11. Seed produced fromsaid hybrid plant of claim 10.